<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			prompt("老师讲解内容");
			var answer=prompt("大家学会了吗y/n");
			var count=1
		while(answer=='n'&&count <=2){
			alert("老师再讲解一遍");
			count++;
		}
		alert("放学")
			
				
			
		</script>
	</body>
</html>
